1. Field of Invention
The present disclosure relates generally to multi-tasking multiprocessor systems, and in particular, to a performance neutral heartbeat for a multi-tasking multiprocessor environment.
2. Description of Background
In many mainframe computers, multiple processors are joined into a single unit, sharing the same name and data sets. Such multi-tasking, multi-processor systems represent an instance of a computer system running on one or more physical computers. These multiple mainframes may act as a single mainframe. Such systems can be broken down into LPARs, or logical partitions, each running a different operating system.
InfiniBand (IB), which is a form of System Area Network (SAN), defines a multicast facility that allows a Channel Adapter (CA) to send a packet to a single address and have it delivered to multiple ports. Each multicast group is assigned a unique address, and end-nodes that wish to participate in a multicast group do so via a ‘Join’ process initiated by the candidate participant with the Subnet Manager. The InfiniBand architecture is described in the InfiniBand standard, which is available at http://www.infinibandta.org and also hereby incorporated by reference.
Currently, many computer communications systems attempt to ensure that any particular connection is still viable. Ensuring for viability can typically be performed at any layer, from hardware through upper level software. A common software approach involves sending heartbeat messages and ensuring that a response is received across the link. In one approach, one end point takes on the role of master, generating the heartbeat messages and checking for responses. The slave end simply receives a heartbeat message responds by sending a heartbeat response message. In another approach, both end points take on both the master and slave roles, generating heartbeat messages, checking for heartbeat responses, and responding to received heartbeat messages by sending a heartbeat response message. One problem that arises from either of these approaches occurs when the traffic level is high. During high traffic times, the heartbeat messages themselves add to the overall congestion on the link.